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heavy slow resistance

Jik Nijssen, Laura H Comley, Eva Hedlund
In the fatal disease-amyotrophic lateral sclerosis (ALS)-upper (corticospinal) motor neurons (MNs) and lower somatic MNs, which innervate voluntary muscles, degenerate. Importantly, certain lower MN subgroups are relatively resistant to degeneration, even though pathogenic proteins are typically ubiquitously expressed. Ocular MNs (OMNs), including the oculomotor, trochlear and abducens nuclei (CNIII, IV and VI), which regulate eye movement, persist throughout the disease. Consequently, eye-tracking devices are used to enable paralysed ALS patients (who can no longer speak) to communicate...
April 13, 2017: Acta Neuropathologica
Davis A Englund, Rick L Sharp, Joshua T Selsby, Shanthi S Ganesan, Warren D Franke
BACKGROUND: The purpose of this study was to compare the effects of high and low velocity knee extension training on changes in muscle strength and mobility status in high-functioning older adults. METHODS: Twenty-six (16 female, 10 male) older adults (mean age of 65) were randomized to either 6weeks of low velocity resistance training (LVRT) performed at 75°/s or high velocity resistance training (HVRT) performed at 240°/s. Both groups performed 3 sets of knee extension exercises at maximal effort, 3 times a week...
May 2017: Experimental Gerontology
B S Shenkman
Skeletal muscle consists of different fiber types arranged in a mosaic pattern. These fiber types are characterized by specific functional properties. Slow-type fibers demonstrate a high level of fatigue resistance and prolonged contraction duration, but decreased maximum contraction force and velocity. Fast-type fibers demonstrate high contraction force and velocity, but profound fatigability. During the last decades, it has been discovered that all these properties are determined by the predominance of slow or fast myosin-heavy-chain (MyHC) isoforms...
October 2016: Acta Naturae
Marija Meznaric, Erika Cvetko
Smaller diaphragmatic motor unit potentials (MUPs) compared to MUPs of limb muscles lead to the hypothesis that diaphragmatic muscle fibers, being the generators of MUPs, might be also smaller. We compared autopsy samples of costal diaphragm and vastus lateralis of healthy men with respect to fibers' size and expression of slow myosin heavy chain isoform (MyHC-1) and fast 2A isoform (MyHC-2A). Diaphragmatic fibers were smaller than fibers in vastus lateralis with regard to the mean minimal fiber diameter of slow-twitch (46...
2016: BioMed Research International
Dimitrios Stasinopoulos, Peter Malliaras
No abstract text is available yet for this article.
November 2016: Journal of Sports Medicine and Physical Fitness
Yin Duan, Lihui Wei, Julia Petryk, Terrence D Ruddy
PURPOSE: When designing liposome formulas for treatment and diagnostic purposes, two of the most common challenges are 1) the lack of a specific release mechanism for the encapsulated contents and 2) a short circulation time due to poor resistance to biological fluids. This study aimed to create a liposome formula with prolonged in vivo longevity and pH-sensitivity for cytoplasmic drug delivery. MATERIALS AND METHODS: Liposomal particles were generated using hydrogenated soy (HS) phosphatidylcholine, cholesteryl hemisuccinate (CHEM), polyethylene glycol (PEG) and diethylenetriaminepentaacetic acid-modified phosphatidylethanolamine with film hydration and extrusion methods...
2016: International Journal of Nanomedicine
Dawid Łochyński, Dominik Kaczmarek, Włodzimierz Mrówczyński, Wojciech Warchoł, Joanna Majerczak, Janusz Karasiński, Michał Korostyński, Jerzy A Zoladz, Jan Celichowski
Dynamic resistance training increases the force and speed of muscle contraction, but little is known about modifications to the contractile properties of the main physiological types of motor units (MUs) that contribute to these muscle adaptations. Although the contractile profile of MU muscle fibers is tightly coupled to myosin heavy chain (MyHC) protein expression, it is not well understood if MyHC transition is a prerequisite for modifications to the contractile characteristics of MUs. In this study, we examined MU contractile properties, the mRNA expression of MyHC, parvalbumin, and sarcoendoplasmic reticulum Ca(2+) pump isoforms, as well as the MyHC protein content after 5 wk of volitional progressive weight-lifting training in the medial gastrocnemius muscle in rats...
October 1, 2016: Journal of Applied Physiology
Wataru Mizunoya, Shinpei Okamoto, Hideo Miyahara, Mariko Akahoshi, Takahiro Suzuki, Mai-Khoi Q Do, Hideaki Ohtsubo, Yusuke Komiya, Mulan Qahar, Toshiaki Waga, Koichi Nakazato, Yoshihide Ikeuchi, Judy E Anderson, Ryuichi Tatsumi
Our previous studies demonstrated that an 8-week intake of 5% (w/w) apple polyphenol (APP) in the diet improves muscle endurance of young-adult rats. In order to identify a lower limit of the dietary contribution of APP to the effect, the experiments were designed for lower-dose supplementation (8-week feeding of 0.5% APP in AIN-93G diet) to 12-week-old male Sprague-Dawley rats. Results clearly showed that the 0.5% APP diet significantly up-regulates slower myosin-heavy-chain (MyHC) isoform ratios (IIx and IIa relative to total MyHC) and myoglobin expression in lower hind-limb muscles examined (P < 0...
March 2017: Animal Science Journal, Nihon Chikusan Gakkaihō
Jared Talbot, Lisa Maves
Skeletal muscle fibers are classified into fiber types, in particular, slow twitch versus fast twitch. Muscle fiber types are generally defined by the particular myosin heavy chain isoforms that they express, but many other components contribute to a fiber's physiological characteristics. Skeletal muscle fiber type can have a profound impact on muscle diseases, including certain muscular dystrophies and sarcopenia, the aging-induced loss of muscle mass and strength. These findings suggest that some muscle diseases may be treated by shifting fiber type characteristics either from slow to fast, or fast to slow phenotypes, depending on the disease...
July 2016: Wiley Interdisciplinary Reviews. Developmental Biology
Jon-Philippe K Hyatt, Lisa Nguyen, Allison E Hall, Ashley M Huber, Jessica C Kocan, Julie A Mattison, Rafael de Cabo, Jeannine R LaRocque, Robert J Talmadge
Shifts in myosin heavy chain (MHC) expression within skeletal muscle can be induced by a host of stimuli including, but not limited to, physical activity, alterations in neural activity, aging, and diet or obesity. Here, we hypothesized that both age and a long-term (2 year) high fat/high sugar diet (HFS) would induce a slow to fast MHC shift within the plantaris, soleus, and extensor digitorum longus (EDL) muscles from rhesus monkeys. Furthermore, we tested whether supplementation with resveratrol, a naturally occurring compound that has been attributed with augmenting aerobic potential through mitochondrial proliferation, would counteract any diet-induced MHC changes by promoting a fast to slow isoform switch...
2016: Frontiers in Physiology
Gerardo Puopolo, Selena Tomada, Paolo Sonego, Marco Moretto, Kristof Engelen, Michele Perazzolli, Ilaria Pertot
Lysobacter capsici AZ78 has considerable potential for biocontrol of phytopathogenic microorganisms. However, lack of information about genetic cues regarding its biological characteristics may slow down its exploitation as a biofungicide. In order to obtain a comprehensive overview of genetic features, the L. capsici AZ78 genome was sequenced, annotated and compared with the phylogenetically related pathogens Stenotrophomonas malthophilia K729a and Xanthomonas campestris pv. campestris ATCC 33913. Whole genome comparison, supported by functional analysis, indicated that L...
2016: Frontiers in Microbiology
Charles A Stuart, William L Stone, Mary E A Howell, Marianne F Brannon, H Kenton Hall, Andrew L Gibson, Michael H Stone
Muscle fiber composition correlates with insulin resistance, and exercise training can increase slow-twitch (type I) fibers and, thereby, mitigate diabetes risk. Human skeletal muscle is made up of three distinct fiber types, but muscle contains many more isoforms of myosin heavy and light chains, which are coded by 15 and 11 different genes, respectively. Laser capture microdissection techniques allow assessment of mRNA and protein content in individual fibers. We found that specific human fiber types contain different mixtures of myosin heavy and light chains...
March 1, 2016: American Journal of Physiology. Cell Physiology
Christian Giordano, Christian Lemaire, Tong Li, R John Kimoff, Basil J Petrof
BACKGROUND: Short-term intermittent hypoxia (IH) is common in patients with acute respiratory disorders. Although prolonged exposure to hypoxia induces atrophy and increased fatigability of skeletal muscle, the response to short-term IH is less well known. We hypothesized that the diaphragm and limb muscles would adapt differently to short-term IH given that hypoxia stimulates ventilation and triggers a superimposed exercise stimulus in the diaphragm. METHODS: We determined the structural, metabolic, and contractile properties of the mouse diaphragm after 4 days of IH (8 hours per day, 30 episodes per hour to a FiO2 nadir=6%), and compared responses in the diaphragm to a commonly studied reference limb muscle, the tibialis anterior...
2015: PloS One
Bernadett Kalmar, Gonzalo Blanco, Linda Greensmith
Skeletal muscles consist of muscle fibers that can differ in both composition and functional characteristics. These three types of muscle fibers, broadly categorized as slow, fast IIa, and fast IIb muscle fibers, express characteristic myosin heavy chain proteins and have different metabolic and enzymatic activities, which can be used as surrogate markers to identify the different fiber types. Pathological changes affecting the muscle, such as denervation, muscle disuse, and atrophy not only manifest on a functional level, but also as marked changes in the composition of muscle fiber type of individual muscles...
2012: Current Protocols in Mouse Biology
Rikke Beyer, Mads Kongsgaard, Birgitte Hougs Kjær, Tommy Øhlenschlæger, Michael Kjær, S Peter Magnusson
BACKGROUND: Previous studies have shown that eccentric training has a positive effect on Achilles tendinopathy, but few randomized controlled trials have compared it with other loading-based treatment regimens. PURPOSE: To evaluate the effectiveness of eccentric training (ECC) and heavy slow resistance training (HSR) among patients with midportion Achilles tendinopathy. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 58 patients with chronic (>3 months) midportion Achilles tendinopathy were randomized to ECC or HSR for 12 weeks...
July 2015: American Journal of Sports Medicine
Alastair Khodabukus, Leslie M Baehr, Sue C Bodine, Keith Baar
The role of factors such as frequency, contraction duration and active time in the adaptation to chronic low-frequency electrical stimulation (CLFS) is widely disputed. In this study we explore the ability of contraction duration (0.6, 6, 60, and 600 sec) to induce a fast-to-slow shift in engineered muscle while using a stimulation frequency of 10 Hz and keeping active time constant at 60%. We found that all contraction durations induced similar slowing of time-to-peak tension. Despite similar increases in total myosin heavy (MHC) levels with stimulation, increasing contraction duration resulted in progressive decreases in total fast myosin...
October 2015: Journal of Cellular Physiology
William J Kraemer, David R Hooper, Tunde K Szivak, Brian R Kupchak, Courtenay Dunn-Lewis, Brett A Comstock, Shawn D Flanagan, David P Looney, Adam J Sterczala, William H DuPont, J Luke Pryor, Hiu-Ying Luk, Jesse Maladoungdock, Danielle McDermott, Jeff S Volek, Carl M Maresh
OBJECTIVE: This study evaluated whether a combination of whey protein (WP), calcium beta-hydroxy-beta-methylbutyrate (HMB), and carbohydrate exert additive effects on recovery from highly demanding resistance exercise. METHODS: Thirteen resistance-trained men (age: 22.6 ± 3.9 years; height: 175.3 ± 12.2 cm; weight: 86.2 ± 9.8 kg) completed a double-blinded, counterbalanced, within-group study. Subjects ingested EAS Recovery Protein (RP; EAS Sports Nutrition/Abbott Laboratories, Columbus, OH) or WP twice daily for 2 weeks prior to, during, and for 2 days following 3 consecutive days of intense resistance exercise...
2015: Journal of the American College of Nutrition
Suresh Sajwan, Roman Sidorov, Tereza Stašková, Anna Žaloudíková, Yoko Takasu, Dalibor Kodrík, Michal Zurovec
Adipokinetic hormones (Akhs) are small peptides (8-10 amino acid [aa] residues long) found in insects that regulate metabolic responses to stress by stimulating catabolic reactions and mobilizing energy stores. We employed Transcription activator-like effector nuclease (TALEN) mutagenesis and isolated an Akh(1) mutant carrying a small deletion in the gene that resulted in a truncated peptide; the second aa (Leu) was missing from the functional octapeptide. This null Dmel/Akh mutant is suitable to study Akh function without any effect on the C-terminal associated peptide encoded by the same gene...
June 2015: Insect Biochemistry and Molecular Biology
Nicholas L Reyes, Glen B Banks, Mark Tsang, Daciana Margineantu, Haiwei Gu, Danijel Djukovic, Jacky Chan, Michelle Torres, H Denny Liggitt, Dinesh K Hirenallur-S, David M Hockenbery, Daniel Raftery, Brian M Iritani
Mammalian skeletal muscle is broadly characterized by the presence of two distinct categories of muscle fibers called type I "red" slow twitch and type II "white" fast twitch, which display marked differences in contraction strength, metabolic strategies, and susceptibility to fatigue. The relative representation of each fiber type can have major influences on susceptibility to obesity, diabetes, and muscular dystrophies. However, the molecular factors controlling fiber type specification remain incompletely defined...
January 13, 2015: Proceedings of the National Academy of Sciences of the United States of America
Alastair Khodabukus, Keith Baar
Satellite cells derived from fast and slow muscles have been shown to adopt contractile and metabolic properties of their parent muscle. Mouse muscle shows less distinctive fiber-type profiles than rat or rabbit muscle. Therefore, in this study we sought to determine whether three-dimensional muscle constructs engineered from slow soleus (SOL) and fast tibialis anterior (TA) from mice would adopt the contractile and metabolic properties of their parent muscle. Time-to-peak tension (TPT) and half-relaxation time (1/2RT) was significantly slower in SOL constructs...
August 2015: Journal of Cellular Physiology
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